Moisture and hydrogen adsorption getter and method of fabricating the same

ABSTRACT

A moisture and hydrogen adsorption getter is provided. The moisture and hydrogen adsorption getter includes a silicon substrate including a concave portion and a convex portion, a silicon oxide layer conformally provided along a surface of the concave portion and a surface of the convex portion and configured to adsorb moisture, and a hydrogen adsorption pattern disposed on the silicon oxide layer. A portion of the silicon oxide layer is exposed between portions of the hydrogen adsorption pattern.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Rule 53(b) Divisional Application of U.S.application Ser. No. 16/175,965 filed Oct. 31, 2018, which is aContinuation Application of International Application No.PCT/KR2016/004745 filed May 4, 2016, claiming priority based on KoreanPatent Application No. 10-2016-0054430 filed May 3, 2016, thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND 1. Field

The present disclosure herein relates to a moisture and hydrogenadsorption getter and a method of fabricating the same, and moreparticularly, to a moisture and hydrogen adsorption getter including asilicon substrate, a silicon oxide layer for adsorbing or absorbingmoisture, and a hydrogen adsorption pattern for adsorbing or absorbinghydrogen, and a method of fabricating the same.

2. Description of the Related Art

Getters may be used in various electronic devices (e.g., displaydevices, semiconductor devices, and IR sensors) which requires innervacuum spaces. In addition, getters have been increasingly demanded withthe rapid development of an electronic industry producing electronicdevices.

A non-evaporated getter (NEG) has been mainly used as an adsorptiongetter. However, the NEG may require a process of heating the NEG to ahigh temperature in an activation process, and thus the NEG may requirea separate heat source device therein. Accordingly, there is a limit tothe miniaturization of an electronic device. To solve the limitation,various getters are being studied.

For example, Korean Patent Publication No. 10-2014-0096047 (ApplicationNo. 10-2014-7011687, Applicant: SAES GETTERS S.p.A.) discloses acomposite getter system which includes a NEG material coated withpolyimide or a polyimide-based compound to obtain an improved compositegetter system.

SUMMARY

The present disclosure may provide a moisture and hydrogen adsorptiongetter with high reliability, an electronic device including the same,and methods of fabricating them.

The present disclosure may also provide a moisture and hydrogenadsorption getter capable of simplifying processes of forming a siliconoxide layer for adsorbing moisture and a hydrogen adsorption pattern,and a method of fabricating the same.

The present disclosure may further provide a low-cost moisture andhydrogen adsorption getter and a method of fabricating the same.

In an aspect, a moisture and hydrogen adsorption getter may include asilicon substrate including a concave portion and a convex portion, asilicon oxide layer conformally provided along a surface of the concaveportion and a surface of the convex portion and configured to adsorbmoisture, and a hydrogen adsorption pattern disposed on the siliconoxide layer. A portion of the silicon oxide layer may be exposed betweenportions of the hydrogen adsorption pattern.

In an embodiment, the silicon substrate may further include a pluralityof holes extending downward from the surfaces of the concave portion andthe convex portion.

In an embodiment, the silicon oxide layer may be conformally providedalong inner surfaces of the holes.

In an embodiment, the moisture and hydrogen adsorption getter mayfurther include a plurality of metal particles provided in the pluralityof holes, respectively.

In an embodiment, the metal particles provided in the holes may includeat least one of Pt, Ag, or Pd.

In an embodiment, the moisture and hydrogen adsorption getter mayfurther include passivation metal catalyst particles provided on thehydrogen adsorption pattern.

In an embodiment, the passivation metal catalyst particles may includeat least one of Ag, Pd, or Pt.

In an embodiment, the hydrogen adsorption pattern may include at leastone of PdO, Rh, or Pt.

In an aspect, an electronic device may include a device substrate havinga sensor part, and the aforementioned moisture and hydrogen adsorptiongetter disposed on the device substrate. The sensor part may face thesilicon oxide layer and the hydrogen adsorption pattern.

In an aspect, a method of fabricating a moisture and hydrogen adsorptiongetter may include preparing a silicon substrate including a concaveportion and a convex portion, forming a silicon oxide layer foradsorbing moisture by immersing the silicon substrate in an acidsolution, and forming a hydrogen adsorption pattern on the silicon oxidelayer.

In an embodiment, the method may further include forming a plurality ofholes extending downward from surfaces of the concave portion and theconvex portion before the forming of the silicon oxide layer.

In an embodiment, the forming of the holes may include forming a metalthin layer on the concave portion and the convex portion, thermallytreating the metal thin layer formed on the concave portion and theconvex portion to form metal particles, and forming the holes extendingdownward from the surfaces corresponding to the metal particles by amethod of etching the silicon substrate including the concave portionand the convex portion by using the metal particles as a catalyst.

In an embodiment, the preparing of the silicon substrate may includeforming a mask film that covers a first region of the silicon substrateand exposes a second region of the silicon substrate, and immersing thesilicon substrate in a basic solution to form the concave portion andthe convex portion on the second region of the silicon substrate.

In an embodiment, the forming of the hydrogen adsorption pattern mayinclude forming a hydrogen adsorption preliminary pattern on the siliconoxide layer, and oxidizing the hydrogen adsorption preliminary patternby a thermal treatment method to form the hydrogen adsorption pattern.

In an embodiment, the method may further include forming passivationmetal catalyst particles on the hydrogen adsorption pattern. The formingof the passivation metal catalyst particles may include forming a metalcatalyst pattern on the hydrogen adsorption pattern, and thermallytreating the metal catalyst pattern to form the passivation metalcatalyst particles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a method of fabricating a moistureand hydrogen adsorption getter according to some embodiments of theinventive concepts.

FIGS. 2 to 9 are cross-sectional views illustrating a method offabricating a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

FIG. 10 is an enlarged view of a portion ‘A’ of FIG. 7.

FIG. 11 is an enlarged view of a portion ‘B’ of FIG. 9.

FIG. 12 is a view illustrating a moisture and hydrogen adsorption getterformed in a region of a silicon substrate in some embodiments of theinventive concepts.

FIG. 13 is a perspective view illustrating an electronic deviceincluding a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

FIG. 14 shows scanning electron microscope (SEM) images of platinumparticles formed in a method of fabricating a moisture and hydrogenadsorption getter according to some embodiments of the inventiveconcepts.

FIG. 15 shows SEM images of a plurality of holes formed using platinumparticles in a method of fabricating a moisture and hydrogen adsorptiongetter according to some embodiments of the inventive concepts.

FIG. 16 shows SEM images of a plurality of holes formed using silverparticles in a method of fabricating a moisture and hydrogen adsorptiongetter according to some embodiments of the inventive concepts.

FIG. 17 shows SEM images of a hydrogen adsorption pattern and apassivation metal catalyst particle formed in a method of fabricating amoisture and hydrogen adsorption getter according to some embodiments ofthe inventive concepts.

FIG. 18 is a graph showing evaluated moisture adsorption characteristicsof a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

FIG. 19 is a graph showing evaluated hydrogen adsorption characteristicsof a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The inventive concepts will now be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the inventive concepts are shown. It should be noted, however, thatthe inventive concepts are not limited to the following exemplaryembodiments, and may be implemented in various forms. Accordingly, theexemplary embodiments are provided only to disclose the inventiveconcepts and let those skilled in the art know the category of theinventive concepts.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may be present. Inaddition, in the drawings, the thicknesses of layers and regions areexaggerated for clarity.

It will be also understood that although the terms first, second, thirdetc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another element. Thus, a first element insome embodiments could be termed a second element in other embodimentswithout departing from the teachings of the present invention. Exemplaryembodiments of aspects of the present inventive concepts explained andillustrated herein include their complementary counterparts. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the invention. As usedherein, the singular terms “a”, “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”,“comprising”, “includes”, “including”, “have”, “has” and/or “having”when used herein, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof. Furthermore, itwill be understood that when an element is referred to as being“connected” or “coupled” to another element, it may be directlyconnected or coupled to the other element or intervening elements may bepresent.

In addition, in explanation of the present invention, the descriptionsto the elements and functions of related arts may be omitted if theyobscure the subjects of the inventive concepts.

A method of fabricating a moisture and hydrogen adsorption getteraccording to some embodiments of the inventive concepts will bedescribed hereinafter.

FIG. 1 is a flowchart illustrating a method of fabricating a moistureand hydrogen adsorption getter according to some embodiments of theinventive concepts, and FIGS. 2 to 9 are cross-sectional viewsillustrating a method of fabricating a moisture and hydrogen adsorptiongetter according to some embodiments of the inventive concepts. FIG. 10is an enlarged view of a portion ‘A’ of FIG. 7, and FIG. 11 is anenlarged view of a portion ‘B’ of FIG. 9.

Referring to FIGS. 1 and 2, a silicon substrate 100 having a concaveportion 102 and a convex portion 104 may be prepared (S110). The siliconsubstrate 100 may be a P-type silicon substrate used as a semiconductormaterial of, for example, an IR sensor.

The preparation of the silicon substrate 100 having the concave portion102 and the convex portion 104 may include cleaning a base siliconsubstrate having a flat surface, and etching the cleaned base siliconsubstrate to form the silicon substrate 100 having the concave portion102 and the convex portion 104.

The cleaning of the base silicon substrate may include removingimpurities of the base silicon substrate, removing an organic materialof the base silicon substrate, and removing a natural oxide layer of thebase silicon substrate. For example, the impurities of the base siliconsubstrate may be removed using acetone and deionized water. For example,the removal of the organic material of the base silicon substrate mayinclude immersing the base silicon substrate in a cleaning solutionwhich has a temperature of 80° C. and includes sulfuric acid, hydrogenperoxide and deionized water mixed with each other at a ratio of 6:3:1,and cleaning the base silicon substrate by deionized water. For example,the removal of the natural oxide layer of the base silicon substrate mayinclude immersing the base silicon substrate in a 10 wt % hydrofluoricacid solution for 10 minutes at room temperature.

The etching of the cleaned base silicon substrate may include immersingthe cleaned base silicon substrate in a basic solution. For example, thebasic solution may include at least one of KOH, (CH₃)₄NOH (TMAH), orNH₄F. For example, the cleaned base silicon substrate may be immersed ina 2 wt % potassium hydroxide solution for 30 minutes to form the siliconsubstrate 100 having the concave portion 102 and the convex portion 104.Thereafter, the silicon substrate 100 having the concave portion 102 andthe convex portion 104 may be cleaned using deionized water and then maybe dried.

Alternatively, a compound semiconductor substrate, a plastic substrateor a glass substrate may be used instead of the silicon substrate 100.

Referring to FIG. 3, metal particles 110 spaced apart from each othermay be formed on the silicon substrate 100 having the concave portion102 and the convex portion 104. The metal particles 110 may be formed onsurfaces of the concave portion 102 and the convex portion 104 of thesilicon substrate 100. For example, an average diameter of the metalparticles 110 may be about 30 nm. For example, the metal particles 110may include at least one of Pt, Ag, or Pd.

The formation of the metal particles 110 may include forming a metalthin layer on the silicon substrate 100 having the concave portion 102and the convex portion 104, and thermally treating the metal thin layerto form the metal particles 110.

In some embodiments, the metal thin layer on the silicon substrate 100having the concave portion 102 and the convex portion 104 may be formedby an electron-beam (e-beam) deposition method. In other embodiments,the metal thin layer may be formed by a chemical vapor deposition (CVD)method, a physical vapor deposition (PVD) method, or an atomic layerdeposition (ALD) method.

The thermal treating of the metal thin layer to form the metal particles110 may include thermally treating the metal thin layer to form themetal particles 110, and air-cooling the silicon substrate 100 to roomtemperature.

For example, when the metal thin layer is a platinum thin layer, theplatinum thin layer may be formed with a thickness of about 10 nm andmay be thermally treated at a temperature of 550° C. to 750° C. for 2hours. In more detail, for example, when the platinum thin layer has thethickness of 10 nm and is thermally treated at 650° C., platinumparticles having an average diameter of about 30 nm may be formed.

For another example, when the metal thin layer is a silver thin layer,the silver thin layer may be formed with a thickness of about 10 nm andmay be thermally treated at a temperature of about 200° C. for 2 hoursto form silver particles.

Referring to FIG. 4, a plurality of holes 120 may be formed to extend orbe recessed downward from the surfaces of the concave portion 102 andthe convex portion 104.

In some embodiments, the plurality of holes 120 may be formed by ametal-assisted chemical etching method using the metal particles 110.For example, when the platinum particles are formed on the surfaces ofthe concave portion 102 and the convex portion 104 as described above,the metal-assisted chemical etching method using the platinum particlesmay include etching the silicon substrate 100 using a HNA solution(HF:HNO₃:acetic acid:deionized water=3:5:3:22) at a temperature of 40°C. for 60 minutes.

If the etching process is performed using a solution includinghydrofluoric acid and hydrogen peroxide unlike the above descriptions,it may be difficult to maintain the shapes of the concave portion 102and the convex portion 104, due to high reactivity between hydrogenperoxide and the platinum particles.

However, according to the aforementioned embodiments of the inventiveconcepts, the plurality of holes 120 may be formed in the siliconsubstrate 100 having the concave portion 102 and the convex portion 104by using the platinum particles and the HNA solution, and thus the shapeof the silicon substrate 100 having the concave portion 102 and theconvex portion 104 may be substantially maintained.

For another example, when the silver particles are formed on thesurfaces of the concave portion 102 and the convex portion 104, ametal-assisted chemical etching method using the silver particles mayinclude etching the silicon substrate 100 using a mixture solution ofhydrofluoric acid and hydrogen peroxide (HF:H₂O₂=10:1) at roomtemperature for a time of 1 minute to 5 minutes. When the holes 120 areformed using the silver particles, the temperature of the thermaltreatment process may be low, a material cost may be reduced, and aprocess time may be reduced.

Alternatively, in other embodiments, the plurality of holes 120 may beformed by an anode oxidation method. For example, the anode oxidationmethod may include applying a current of 1 mA/cm² using the siliconsubstrate 100 as an anode.

When the holes 120 are formed by the anode oxidation method, depths ofthe holes 120 may be adjusted depending on an applying time of thecurrent and a kind and a ratio of a solution. In addition, the pluralityof holes 120 may be formed at low temperature by a simple process, andthus a fabrication cost may be reduced.

Referring to FIGS. 1 and 5, the silicon substrate 100 which has theconcave portion 102 and the convex portion 104 and in which theplurality of holes 120 is formed may be immersed in an acid solution toform a silicon oxide layer 200 for adsorbing moisture (S120). Forexample, the acid solution may include at least one of nitric acid oracetic acid.

The immersion of the silicon substrate 100 having the concave portion102, the convex portion 104 and the holes 120 in the acid solution mayinclude a first process of immersing the silicon substrate 100 in afirst acid solution for a first time, and a second process of immersingthe silicon substrate 100 for a second time longer than the first timein a second acid solution of which a temperature or a concentration isdifferent from that of the first acid solution.

For example, the first immersion process may include immersing thesilicon substrate 100 in a 40 wt % nitric acid solution of 110° C. for10 minutes. For example, the second immersion process may includeimmersing the silicon substrate 100, on which the first immersionprocess is performed, in a 70 wt % nitric acid solution of 120° C. for 2hours.

As described above, the silicon oxide layer 200 for adsorbing moisturemay be formed by the simple solution process of immersing the siliconsubstrate 100 having the concave portion 102, the convex portion 104 andthe holes 120 in the acid solution. Thus, the silicon oxide layer 200may be conformally formed on inner surfaces of the holes 120 and asurface outside the holes 120. The surface outside the holes 120 may bereferred to as an outer surface of the holes 120. When the acid solutionis the nitric acid solution as described above, the silicon oxide layer200 may be formed as the following chemical formula 1.Si+4HNO₃→SiO₂+2H₂O+4NO₂  [Chemical formula 1]

However, if a moisture adsorbing layer is formed by a CVD method, a PVDmethod or an ALD method unlike the embodiments of the inventiveconcepts, it may not be easy to form the moisture adsorbing layer on theinner surfaces of the holes 120, due to a high aspect ratio of the holes120. In addition, since a vacuum chamber is used, a fabrication cost maybe increased and a fabricating process may be complicated.

However, according to the aforementioned embodiments of the inventiveconcepts, the silicon oxide layer 200 for adsorbing moisture may beformed by the simple solution process of immersing the silicon substrate100 in the acid solution, and thus it is possible to provide the methodof fabricating the moisture and hydrogen adsorption getter, which iscapable of reducing the fabrication cost and of simplifying thefabricating processes.

The metal particles 110 may remain in the holes 120.

Referring to FIG. 6, a hydrogen adsorption preliminary pattern 210 maybe formed on the silicon oxide layer 200. For example, the hydrogenadsorption preliminary pattern 210 may include at least one of Pd, Rh,or Pt. For example, the hydrogen adsorption preliminary pattern 210 maybe formed by an e-beam deposition method, a CVD method, a PVD method, oran ALD method.

According to some embodiments of the inventive concepts, the hydrogenadsorption preliminary pattern 210 may be mainly formed on the outersurface of the plurality of holes 120 by the high aspect ratio of theholes 120. Thus, portions of the silicon oxide layer 200 which aredisposed on the inner surfaces of the holes 120 may not be covered bythe hydrogen adsorption preliminary pattern 210, but another portion ofthe silicon oxide layer 200 which is disposed on the outer surface ofthe holes 120 may be covered by the hydrogen adsorption preliminarypattern 210. In other words, the silicon oxide layer 200 on the innersurfaces of the holes 120 may be exposed. Moisture may be easilyadsorbed by the silicon oxide layer 200 which is disposed on the innersurfaces of the holes 120 and thus is exposed.

Referring to FIGS. 1, 7 and 10, a hydrogen adsorption pattern 220 may beformed on the silicon oxide layer 200 (S130). The silicon oxide layer200 for adsorbing moisture may be exposed between portions of thehydrogen adsorption pattern 220.

The hydrogen adsorption pattern 220 may be formed by thermally treatingthe hydrogen adsorption preliminary pattern 210. For example, when thehydrogen adsorption preliminary pattern 210 is formed of palladium, apalladium pattern of 100 nm may be deposited by an e-beam depositionmethod, and the palladium pattern may be thermally treated at 300° C. toform the hydrogen adsorption pattern 220 including palladium oxide. Whenthe hydrogen adsorption pattern 220 includes the palladium oxide, thepalladium oxide may adsorb hydrogen as the following chemical formula 2.PdO(s)+H₂(g)→Pd(s)+H₂O(l)  [Chemical formula 2]

Unlike the embodiments described above, the process of thermallytreating the hydrogen adsorption preliminary pattern 210 may be omitted.In this case, the hydrogen adsorption preliminary pattern 210 may adsorbhydrogen.

Referring to FIG. 8, a passivation layer 240 may be formed on thehydrogen adsorption pattern 220.

In some embodiments, the passivation layer 240 may be formed using ane-beam deposition method. In other embodiments, the passivation layer240 may be formed by a CVD method, a PVD method, or an ALD method. Forexample, the passivation layer 240 may include at least one of Ag, Pd,or Pt.

The passivation layer 240 may be deposited on the hydrogen adsorptionpattern 220 and may cover the silicon oxide layer 200 and the hydrogenadsorption pattern 220 to inhibit the hydrogen adsorption pattern 220and the silicon oxide layer 200 from being exposed to an externalenvironment. Thus, the hydrogen adsorption pattern 220 and the siliconoxide layer 200 may be protected. For example, the passivation layer 240may protect the hydrogen adsorption pattern 220 and the silicon oxidelayer 200 from various post-treatment processes (e.g., a process exposedto the atmosphere, a cleaning process, a plasma process, and/or ahigh-pressure process) performed before the moisture and hydrogenadsorption getter including the silicon oxide layer 200 and the hydrogenadsorption pattern 220 is coupled to an electronic device.

Referring to FIGS. 1, 9 and 11, passivation metal catalyst particles 250may be formed on the hydrogen adsorption pattern 220 (S140).

The passivation metal catalyst particles 250 may be formed by thermallytreating the passivation layer 240. For example, when the passivationlayer 240 is a silver thin layer, the silver thin layer may be depositedwith a thickness of 10 nm and then may be thermally treated at 300° C.to form silver catalyst particles.

According to some embodiments, the hydrogen adsorption pattern 220 maybe exposed between the passivation metal catalyst particles 250.

The passivation metal catalyst particles 250 may improve characteristicsof the hydrogen adsorption pattern 220 and the silicon oxide layer 200in such a way that the hydrogen adsorption pattern 220 and the siliconoxide layer 200 easily adsorb hydrogen and moisture under a high-vacuumcondition.

In addition, a temperature at which the passivation layer 240 isthermally treated to form the passivation metal catalyst particles 250may be substantially equal to or similar to a temperature of a processof adhering the getter including the silicon oxide layer 200 and thehydrogen adsorption pattern 220 to the electronic device and atemperature of a process of cleaning the electronic device and thegetter. Thus, an additional thermal treatment process for forming thepassivation metal catalyst particles 250 from the passivation layer 240may be omitted.

According to other embodiments of the inventive concepts, the formationof the passivation layer 240 and the passivation metal catalystparticles 250 may be omitted.

According to the embodiments of the inventive concepts, the moisture andhydrogen adsorption getter including the hydrogen adsorption pattern 220and the silicon oxide layer 200 for adsorbing moisture may be coupled tothe electronic device to prevent the electronic device from beingdeteriorated by moisture and hydrogen. Hereinafter, this will bedescribed in detail with reference to FIGS. 12 and 13.

FIG. 12 is a view illustrating a moisture and hydrogen adsorption getterformed in a region of a silicon substrate in some embodiments of theinventive concepts.

Referring to FIG. 12, the silicon substrate 100 described with referenceto FIGS. 1 to 11 may include a first region 100A covered by a mask film100C and a second region 100B not covered by the mask film 100C. Theconcave portion 102, the convex portion 104, the plurality of holes 120,the silicon oxide layer 200 for adsorbing moisture, the hydrogenadsorption pattern 220 and the passivation metal catalyst particles 250,which are described with reference to FIGS. 1 to 11, may be formed onthe second region 100B of the silicon substrate 100.

Thus, the preparation of the silicon substrate 100, described withreference to FIGS. 1 and 2, may include forming the mask film 100C onthe first region 100A of the silicon substrate 100 to expose the secondregion 100B of the silicon substrate 100, and immersing the siliconsubstrate 100 in the basic solution to form the concave portion 102 andthe convex portion 104, described in FIGS. 1 to 11, on the second region100B of the silicon substrate 100.

After the formation of the concave portion 102 and the convex portion104, the plurality of holes 120, the silicon oxide layer 200 foradsorbing moisture, the hydrogen adsorption pattern 220 and thepassivation metal catalyst particles 250 may be sequentially formed asdescribed with reference to FIGS. 1 to 11. The mask film 100C may beremoved after the formation of the passivation metal catalyst particles250.

After the moisture and hydrogen adsorption getter is formed on thesecond region 100B described with reference to FIG. 12, the moisture andhydrogen adsorption getter may be coupled to the electronic device.Hereinafter, this will be described with reference to FIG. 13.

FIG. 13 is a perspective view illustrating an electronic deviceincluding a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

Referring to FIG. 13, the electronic device in which the moisture andhydrogen adsorption getter is used may include a device substrate 300having a sensor part 310, and the silicon substrate 100 including themoisture and hydrogen adsorption getter 100E fabricated as describedwith reference to FIGS. 1 to 12.

In some embodiments, the device substrate 300 may be coupled to thesilicon substrate 100 in such a way that the sensor part 310 faces thesilicon oxide layer 200 and the hydrogen adsorption pattern 220.

Thus, the silicon oxide layer 200 may adsorb moisture, and the hydrogenadsorption pattern 220 may adsorb hydrogen. As a result, it is possibleto inhibit the sensor part 310 from being deteriorated by moisture andhydrogen.

In the embodiment of FIG. 13, the device substrate 300 having the sensorpart 310 is coupled to the silicon substrate 100 including the moistureand hydrogen adsorption getter 100E fabricated according to FIGS. 1 to12 in the electronic device. However, embodiments of the inventiveconcepts are not limited thereto. In other embodiments, the moisture andhydrogen adsorption getter 100E may be coupled to at least one of othervarious devices such as memory devices and application processors (APs).

Detailed experimental examples of the method of fabricating the moistureand hydrogen adsorption getter according to the embodiments of theinventive concepts will be described hereinafter.

FIG. 14 shows scanning electron microscope (SEM) images of platinumparticles formed in a method of fabricating a moisture and hydrogenadsorption getter according to some embodiments of the inventiveconcepts.

Referring to FIG. 14, a P-type silicon substrate was prepared.Impurities of the silicon substrate were removed using acetone anddeionized water. In addition, the silicon substrate was immersed in acleaning solution (80° C.) including sulfuric acid, hydrogen peroxideand deionized water mixed with each other at a ratio of 6:3:1 and thenwas cleaned by deionized water, and thus an organic material of thesilicon substrate was removed. Furthermore, the silicon substrate wasimmersed in a 10 wt % hydrofluoric acid solution at room temperature for10 minutes to remove a natural oxide layer of the silicon substrate.

Thereafter, the silicon substrate from which the impurities, the organicmaterial and the natural oxide layer were removed was immersed in a 2 wt% potassium hydroxide solution for 30 minutes to form a concave portionand a convex portion according to the embodiments of the inventiveconcepts.

Subsequently, a platinum thin layer having a thickness of 10 nm wasformed on the concave portion and the convex portion by an e-beamdeposition method.

Thereafter, the platinum thin layers were thermally treated at 550° C.,650° C., and 750° C., respectively, to form platinum particles. SEMimages (a), (b) and (c) of FIG. 14 show the platinum particles formed bythermally treating the platinum thin layers at 550° C., 650° C., and750° C., respectively.

As shown in the SEM image (a) of FIG. 14, when the platinum thin layeris thermally treated at 550° C., the platinum particle is not easilyformed. As shown in the SEM image (c) of FIG. 14, when the platinum thinlayer is thermally treated at 750° C., coarse platinum particles areformed. As shown in the SEM image (b) of FIG. 14, when the platinum thinlayer is thermally treated at 650° C., the platinum particles having anaverage diameter of about 30 nm are uniformly formed. Thus, the platinumthin layer may be thermally treated at a temperature greater than 550°C. and less than 750° C. to effectively form the platinum particles.

FIG. 15 shows SEM images of a plurality of holes formed using platinumparticles in a method of fabricating a moisture and hydrogen adsorptiongetter according to some embodiments of the inventive concepts.

Referring to FIG. 15, a plurality of holes was formed in the siliconsubstrate by using the platinum particles formed by thermally treatingthe platinum thin layer at 650° C. in the method described withreference to FIG. 14. In detail, the silicon substrate including theconcave portion and the convex portion on which the platinum particleswere formed was etched using a HNA solution (HF:HNO₃:aceticacid:deionized water=3:5:3:22) at 60° C. for 6 hours to form the holeshaving depths of about 100 nm.

FIG. 16 shows SEM images of a plurality of holes formed using silverparticles in a method of fabricating a moisture and hydrogen adsorptiongetter according to some embodiments of the inventive concepts.

Referring to FIG. 16, silver particles were formed on the siliconsubstrate cleaned and dried by the method described with reference toFIG. 14, and a plurality of holes was formed in the silicon substrate byusing the silver particles.

A silver thin layer having a thickness of about 10 nm was deposited onthe silicon substrate by an e-beam deposition method, and then, thedeposited silver thin layer was thermally treated at 200° C. for 2 hoursto form the silver particles.

The silicon substrates were etched using a solution (hydrofluoricacid:hydrogen peroxide=10:1) at room temperature for 1 minute, 3minutes, and 5 minutes, respectively, thereby forming the holes usingthe silver particles. SEM images (a), (b) and (c) of FIG. 16 show theholes formed by etching the silicon substrates having the silverparticles for 1 minute, 3 minutes, and 5 minutes, respectively.

As shown in the SEM image (a) of FIG. 16, when the silicon substratehaving the silver particles is etched for 1 minute, the holes are noteasily formed. As shown in the SEM image (c) of FIG. 16, when thesilicon substrate having the silver particles is etched for 5 minutes,structures of the holes collapse. As shown in the SEM image (b) of FIG.16, when the silicon substrate having the silver particles is etched for3 minutes, the holes having appropriate depths are formed. Thus, thesilicon substrate may be etched using the silver particles for a timegreater than 1 minute and less than 5 minutes to effectively form theplurality of holes.

FIG. 17 shows SEM images of a hydrogen adsorption pattern and apassivation metal catalyst particle formed in a method of fabricating amoisture and hydrogen adsorption getter according to some embodiments ofthe inventive concepts.

Referring to FIG. 17, a silicon oxide layer was formed on the siliconsubstrate including the concave portion, the convex portion and theholes, formed by the methods described with reference to FIGS. 14 and15. A palladium layer having a thickness of about 100 nm was depositedas a hydrogen adsorption preliminary pattern on the silicon oxide layerby an e-beam deposition method, and then, the deposited palladium layerwas thermally treated at 300° C. to form palladium oxide correspondingto a hydrogen adsorption pattern. A SEM image (a) of FIG. 17 wasobtained from the palladium oxide.

A silver layer having a thickness of about 10 nm was deposited as apassivation layer on the palladium oxide, and then, a SEM image (b) ofFIG. 17 was obtained from the silver layer.

The silver layer deposited on the palladium oxide was thermally treatedat 300° C. to form silver particles as passivation metal catalystparticles, and a SEM image (c) of FIG. 17 was obtained from the silverparticles.

FIG. 18 is a graph showing evaluated moisture adsorption characteristicsof a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

Referring to FIG. 18, moisture adsorption characteristics of a moistureand hydrogen adsorption getter which included the hydrogen adsorptionpattern including the palladium oxide and the silicon oxide layer foradsorbing moisture formed by the method described with reference to FIG.17 were evaluated.

The moisture and hydrogen adsorption getter was heated at 300° C. for 24hours in a vacuum to remove moisture and a gas which remained in themoisture and hydrogen adsorption getter, and then, the moistureadsorption characteristic evaluation of the moisture and hydrogenadsorption getter was performed using tertiary deionized water which hada density of 0.997 g/cm³ and a saturated vapor pressure of 3.1690 kPa(23.8 mmHg) and was heated to 80° C.

In addition, the moisture adsorption characteristic evaluation of themoisture and hydrogen adsorption getter was measured while maintaining atemperature of 25.15° C. At this time, an apparatus for the measurementwas a BELSORP-aqua3 of the BEL Japan company, and isothermal adsorptionand desorption curves of the moisture and hydrogen adsorption getterwere obtained by a volume method as shown in FIG. 18.

A moisture adsorption capacity is generally based on a volume value ofmoisture adsorbed under a condition of relative humidity of 35%, and amoisture adsorption capacity value of the moisture and hydrogenadsorption getter including the silicon oxide layer according to theinventive concepts was 6.251%. Thus, the silicon oxide layer may beusable as a moisture getter material.

FIG. 19 is a graph showing evaluated hydrogen adsorption characteristicsof a moisture and hydrogen adsorption getter according to someembodiments of the inventive concepts.

Referring to FIG. 19, hydrogen adsorption characteristics of themoisture and hydrogen adsorption getter which included the hydrogenadsorption pattern including the palladium oxide and the silicon oxidelayer for adsorbing moisture formed by the method described withreference to FIG. 17 were evaluated.

The moisture and hydrogen adsorption getter was heated at 90° C. for 30minutes in a vacuum and was heated at 300° C. for 4 hours in a vacuum toremove moisture and a remaining gas in the moisture and hydrogenadsorption getter, and then, the hydrogen adsorption characteristicevaluation of the moisture and hydrogen adsorption getter was performedat room temperature. As a result of this evaluation, the hydrogenadsorption characteristics of 0.01 mmol/g or more are shown in an entirepressure range without an additional activation process, as shown inFIG. 19. Thus, the hydrogen adsorption pattern including the palladiumoxide may be usable as a hydrogen getter material.

The moisture and hydrogen adsorption getter according to the embodimentsof the inventive concepts may be coupled to various electronic devices(e.g., sensors, memory devices, and/or CPU) to inhibit or prevent theelectronic devices from being deteriorated by moisture and hydrogen.

The moisture and hydrogen adsorption getter according to the embodimentsof the inventive concepts may include the substrate including theconcave portion and the convex portion, the silicon oxide layerconformally provided along the surfaces of the concave portion and theconvex portion and configured to adsorb moisture, and the hydrogenadsorption pattern disposed on the silicon oxide layer. A portion of thesilicon oxide layer may be exposed between portions of the hydrogenadsorption pattern, and thus moisture as well as hydrogen may be easilyadsorbed. In addition, the silicon oxide layer may be formed by themethod of immersing the substrate including the concave and convexportions in the acid solution. Thus, the fabricating processes of themoisture and hydrogen adsorption getter may be simplified, and thefabrication cost thereof may be reduced.

Moreover, according to the embodiments of the inventive concepts, themoisture and hydrogen adsorption getter may include the plurality ofholes extending downward from the surfaces of the concave portion andthe convex portion. The silicon oxide layer may be formed by the methodof immersing the substrate in the acid solution as described above, andthus the silicon oxide layer may be conformally formed along the innersurfaces of the holes. As a result, a surface area of the silicon oxidelayer for adsorbing moisture may be increased. In addition, even thoughthe hydrogen adsorption pattern is formed on the silicon oxide layer, aportion of the silicon oxide layer may be exposed, and thus it ispossible to provide the moisture and hydrogen adsorption getter of whichadsorption rates of moisture and hydrogen are improved.

While the inventive concepts have been described with reference toexemplary embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirits and scopes of the inventive concepts. Therefore, itshould be understood that the above embodiments are not limiting, butillustrative. Thus, the scopes of the inventive concepts are to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing description.

What is claimed is:
 1. A method of fabricating a moisture and hydrogenadsorption getter, the method comprising: preparing a silicon substrateincluding a concave portion and a convex portion; forming a plurality ofholes extending downward from surfaces of the concave portion and theconvex portion, wherein a plurality of metal particles is provided inthe plurality of holes, forming a silicon oxide layer for adsorbingmoisture; and forming a hydrogen adsorption pattern on the silicon oxidelayer.
 2. A method of fabricating a moisture and hydrogen adsorptiongetter, the method comprising: preparing a silicon substrate including aconcave portion and a convex portion; forming a plurality of holesextending downward from surfaces of the concave portion and the convexportion, wherein a plurality of metal particles is provided in theplurality of holes, forming a silicon oxide layer for adsorbing moistureby immersing the silicon substrate in an acid solution; and forming ahydrogen adsorption pattern on the silicon oxide layer.
 3. The method ofclaim 2, further comprising: forming a plurality of holes extendingdownward from surfaces of the concave portion and the convex portionbefore the forming of the silicon oxide layer.
 4. The method of claim 2,wherein the preparing of the silicon substrate comprises: forming a maskfilm that covers a first region of the silicon substrate and exposes asecond region of the silicon substrate; and immersing the siliconsubstrate in a basic solution to form the concave portion and the convexportion on the second region of the silicon substrate.
 5. The method ofclaim 2, wherein the forming of the hydrogen adsorption patterncomprises: forming a hydrogen adsorption preliminary pattern on thesilicon oxide layer; and oxidizing the hydrogen adsorption preliminarypattern by a thermal treatment method to form the hydrogen adsorptionpattern.
 6. A method of fabricating a moisture and hydrogen adsorptiongetter, the method comprising: preparing a silicon substrate including aconcave portion and a convex portion; forming a silicon oxide layer foradsorbing moisture by immersing the silicon substrate in an acidsolution; and forming a hydrogen adsorption pattern on the silicon oxidelayer, forming a plurality of holes extending downward from surfaces ofthe concave portion and the convex portion before the forming of thesilicon oxide layer, wherein the forming of the holes comprises: forminga metal thin layer on the concave portion and the convex portion;thermally treating the metal thin layer formed on the concave portionand the convex portion to form metal particles; and forming the holesextending downward from the surfaces corresponding to the metalparticles by a method of etching the silicon substrate including theconcave portion and the convex portion by using the metal particles as acatalyst.
 7. A method of fabricating a moisture and hydrogen adsorptiongetter, the method comprising: preparing a silicon substrate including aconcave portion and a convex portion; forming a silicon oxide layer foradsorbing moisture by immersing the silicon substrate in an acidsolution; forming a hydrogen adsorption pattern on the silicon oxidelayer; and forming passivation metal catalyst particles on the hydrogenadsorption pattern, wherein the forming of the passivation metalcatalyst particles comprises: forming a metal catalyst pattern on thehydrogen adsorption pattern; and thermally treating the metal catalystpattern to form the passivation metal catalyst particles.